OBJECTIVES: To give a report on the progress in physical examination, investigations and treatment of diffuse cervical cellulites (DCC) associated with descending necrotizing mediastinitis. MATERIALS AND METHODS: A Retrospective study (1995-2005) of patients presenting DCC with mediastinitis was made. All had a cervical and thoracic Computed tomography (CT) scan. The references were collected by a Medline search. RESULTS: Six men and 2 women, average ages 53 years were treated. Four had an immunodeficient status. Two had had an anti-inflammatory drug treatment without antibiotic treatment. The average for diagnosis and treatment was 4 days. In 2 cases we found a dental origin and in 6 cases a pharyngeal origin. The most frequently identified germs were streptococcus beta haemolytic group A and Prevotella. In 4 cases, no physical sign of mediastinitis was noted. The diagnosis of mediastinitis was made thanks to the thoracic CT scan. All the patients were treated by broad-spectrum antibiotic therapy. All had cervical and thoracic surgical drainage. Mediastinal drainage was made by cervical way in 3 cases and by thoracotomy in 5 cases. One patient died. CONCLUSIONS: The DCC with mediastinum extension are serious infectious emergencies with a high mortality rate. Clinical diagnosis of mediastinitis is difficult. A thoracic CT scan should be performed systematically. Performing thoracotomy best controls mediastinal drainage.